The present invention relates to a disposable diaper or incontinent pad having a pleated attachment strap which is inexpensive and easily manufactured and which offers improved comfort to the wearer.
Disposable diapers for infant and toddler use have been generally available for approximately two decades. Typical products of this type are described in U.S. Pat. Nos. 3,612,055 to Mesek, et al. and Re. 26,151 to Duncan. Innumerable improvements have been made over the years to these rather basic designs. One of the more useful improvements has been the development of adhesively coated tape systems to replace pins or other fasteners for holding the diaper in place on a baby. A large body of patent literature has developed dedicated exclusively to improvements in attachment tapes. The interested reader will find a good historical review of this technology in U.S. Pat. No. 4,014,339 to Tritsch.
Early manufacturers of diapers using tape closure systems faced a number of technical problems. Initially the tape closures projected from the marginal edges of the diapers. These projecting tapes caused serious problems during manufacturing. Torn diaper covers and missing tapes were a frequent occurrence due to snagging on conveyor lines and packaging equipment. A relatively early patent to Hoey, U.S. Pat. No. 3,776,234, describes an attachment tape folded inwardly to prevent interference with manufacturing equipment. Nonprojecting tapes soon became quite standard as methods were developed by other inventors to retain them entirely within the rectangular outline of the diaper until the time of use. At the same time, methods were developed to hold the tape closures flat against the body of the diaper in order to further minimize the risk of snagging. Tritsch, in U.S. Pat. No. 3,930,502, shows a tape folded in "S" fashion. Aldinger, U.S. Pat. No. 3,952,744, shows a folded tape with one end of a strippable release paper attached to the diaper back in order to hold the tape flat and in a noninterfering position during further manufacturing steps. Similar arrangements are also shown in U.S. Pats. Nos. 3,901,239 to Tritsch; 3,999,544 to Feldman, et al.; and 4,060,085 to Karami.
It has only been in the last several years that disposable diapers have been available in larger sizes for use by incontinent adults. The design of these adult products has been much more complex than making a simple scale-up of diapers originally designed for infants. For one thing, the body sizes of the wearers vary greatly. A product which might be inadequately small for one person may be unacceptably sloppy when worn by another individual. As with products designed for infants, a tight, snug fit is essential if leakage is to be prevented. For this reason, adult products are normally available in several sizes. This problem has further complicated the use of closure tabs. Nowakoski, in U.S. Pat. No. 4,317,449, shows a Z-shaped tab which expands to form a short strap. The inventor notes that these tapes may be as long as 17.5 cm (7 in.) and comments that tapes of this length have never before been used on a disposable diaper product. Judging from the patent drawings, the Nowakoski incontinent pad is an extremely wide product which is designed to completely encircle the hip area of the wearer. Products of this type have not generally been found to be acceptable because they tend to bunch up very badly in the crotch area and are both uncomfortable and prone to leakage. More recent products are much narrower so that they resemble a loincloth with the hip area remaining uncovered. These products have required much longer closure straps than those described by Nowakoski with the lengths generally varying from about 18-46 cm (7-18 in.). These tapes generally encircle the waist area of the wearer and act in the manner of a belt.
While the open-sided adult incontinent pads have greatly increased the comfort to the wearer and reduced the chances of leakage, the necessary longer attachment tapes have proved to be a manufacturing nightmare. No longer can they be formed into a simple Z-fold as was done by Nowakoski. One commercially available product is made with the tapes accordion pleated with spots of an adhesive having a low bonding strength placed between each of the pleats to prevent them from springing apart during manufacture. Making a product of this type is complex and expensive and an improved design for these tapes has been a long-sought goal.
The present invention is a major step forward in the design of long attachment tapes or straps for use with adult incontinent products.